How to animate a colour change along a section of a cylinder?
As Alexis King says, you can unwrap your cylinder with the Follow Active Quads method in order to have an orthogonal grid (make sure that your topology has quads that are rather the same size):

Then give it this node setup: Texture Coordinate (UV output) &gt; Mapping &gt; ColorRamp (in Constant mode and with your main and stripe colors) &gt; Diffuse &gt; Output. Now you just need to keyframe the Mapping &quot;Location&quot; values to move the stripe along the cylinder: